LTE system performance optimization by discard timer based PDCP buffer management

Long Term Evolution (LTE) provides a new radio technology that allows operators to achieve even higher peak throughputs than HSPA+. One of the LTE system performance optimization point is the PDCP buffer management mainly at the downlink. PDCP buffers at the eNodeB (eNB) hold user data before it is selected by MAC scheduler for transmission over radio interface. This buffered data also contributes towards X2 traffic volume and required handover completion time during inter-eNB handover events. A buffer management scheme is required to keep PDCP buffer occupancy to a minimal level without a noticeable degradation in user application performance. In other word it should hold sufficient data to optimize the radio performance at Uu interface. This is a challenging issue for the mobile network operator and has to be thoroughly investigated and analyzed. This work suggests a novel buffer management scheme for PDCP buffers at eNB and provides a thorough study of its performance for several real world scenarios. Through an intensive set of simulations, the effectiveness of proposed PDCP buffer management scheme in achieving an optimal PDCP buffer occupancy is proved. Furthermore configuration parameters are suggested to achieve optimum LTE system performance using the proposed scheme.